Apparatus for shutting down an internal combustion engine upon the occurrence of a crankcase explosion therein



Dec. 5, 1967 c. PARSONS 3,356,034

APPARATUS FOR SHUTTING DOWN AN INTERNAL: COMBUSTION ENGINE UPON THE OCCURRENCE OF A CRANKCASE EXPLOSION THEREIN 3 Sheets-Sheet 2 Filed Aug. 31, 1966 INVENTOR CI'iARLES L.PARSONS ATTORNEY)" Dec. 5, 1967 c. L. PARSONS APPARATUS FOR SHUTTING DOWN AN INTERNAL COMBUSTION ENGINE UPON THE OCCURRENCE OF A CRANKCASE EXPLOSION THEREIN 5 Sheets$heet 1 Filed Aug. 31, 1966 CHARLES L. PARSONS ATTORNEYS Dec. 5, 1967 c. L. PARSONS APPARATUS FOR SHUTTING DOWN AN INTERNAL COMBUSTION ENGINE UPON THE OCCURRENCE OF A CRANKCASE EXPLOSION THEREIN Sheet 5 Filed Aug. 31, 1966 POWER SUPPLY 3 Sheecs *RELAY SOL ND ENGINE FUEL FIG. '7.

IINVIENTOR CHARLES L. PARSONS BY W72, Wm

' ATTORNEYJ' United States Patent 3,356,084 APPARATUS FOR SHUTTING DOWN AN INTER- NAL COMBUSTION ENGINE UPON THE OC- CURRENCE OF A CRANKCASE EXPLOSION THEREIN Charles L. Parsons, RD. 2, Coming, N.Y. 14830 Filed Aug. 31, 1966, Ser. No. 576,373 10 Claims. (Cl. 123-198) This invention relates to safety devices for automatically shutting down internal combustion engines, particularly diesel and gas engines, upon the occurrence of crankcase explosions therein, even when the pressure within the crankcase created by an explosion is relatively low.

One of the principal objects of the invention is to provide a low-cost, trouble-free device of simple construction which is particularly adapted for use in combination with known forms of crankcase explosion relief valves, and is capable of automatically shutting off the supply of fuel to an internal combustion engine, or of opening or closing an electrical circuit controlling operation of the engine, whenever an explosion occurs in the engine crankcase, so as to prevent damage to the engine which might result from continued operation thereof.

Another object is the provision of an automatic shut down device which can be quickly and easily installed on engines equipped with crankcase explosion relief valves having valve members which move outwardly in response to increases in the gas pressure in the crankcase in excess of a predetermined value on the order of 1 lb. per square inch or can be combined with such a relief valve and a crankcase inspection door to provide a readily installable unitary assembly.

A further object is to provide a safety device of the character described which must be manually reset after a crankcase explosion before the engine can be restarted.

These and other objectives of the invention, including the provision of an engine shut down device of novel construction which will operate reliably after initial installation without adjustment, maintenance or repairs over long periods of time, will appear more fully upon consideration of the detailed disclosure which follows. In this connection, although three specific embodiments of the invention are described and illustrated in the accompanying drawings, it is to be expressly understood that these drawings are for purposes of illustration only and are not to be construed as defining the limits of the invention, for which latter purpose reference should be had to the appended claims.

In the drawings, wherein like reference characters indicate like parts throughout the several views:

FIG. 1 is a diagrammatic view of a diesel engine fitted with a plurality of crankcase explosion relief valves and pneumatic shut down devices in accordance with the present invention;

FIG. 2 is a perspective view of one of the crankcase doors, relief valves and shut down devices of the installation illustrated in FIG. 1, part of the relief valve cover being broken away, and including a showing of the connection between the shut down device and an air pressure line connected to a pressure responsive valve for controlling the supply of fuel to the engine;

FIG. 3 is a vertical cross-sectional view, partially broken away, of the crankcase door, relief valve and shut olf device assembly of FIG. 2 taken on a vertical plane through the central axis of the relief valve;

FIG. 4 is an enlarged side view, partially in section, of the pneumatic shut down device of FIGS. 13 as it would appear prior to assembly with the relief valve;

FIG. 5 is a vertical cross-sectional view of the shut down device taken on the line 55 in FIG. 4;

FIG. 6 is a fragmentary perspective, partially diagrammatic, view of a second form of the invention embodying an electrical shut down device for controlling operation of an engine magneto; and

FIG. 7 is a diagrammatic view of another embodiment wherein an electrical shut down device is used to control the supply of fuel to the engine.

Referring now to the drawings, FIG. 1 illustrates the application of safety devices embodying the present invention to a diesel engine 10 to which fuel is supplied through a fuel line 11 by a pump 12 in conventional manner. Interposed in the fuel line 11 between the pump 12 and the injectors (not shown) is a pressure responsive control valve 13, of the bellows type or any other suitable construction, which, during normal operation of the engine, is maintained in open position by air under pres sure supplied to the valve through an air line 14 from any suitable source (not shown), such as the receiver of an air compressor, or a starting air tank associated with the engine. In the installation illustrated, the air line 14 is provided with a pressure regulator 15 of conventional construction which normally maintains the air in line 14 at a substantially constant pressure of approximately 25 lbs. per square inch.

The crankcase wall 'of engine 10 is provided in the usual manner with a plurality of inspection ports each of which is normally closed by a removable door 16 on which is mounted a low pressure relief valve 17 adapted to open and release the gas pressure in the crankcase whenever a crankcase explosion occurs which raises said pressure above about 1 lb. per square inch. It should be readily apparent that the explosive mixture in the crankcase, in the case of a diesel engine, is an oil mist rather than what is commonly thought of as a gas. Accordingly, when reference is hereinafter made to gas pressure in the crankcase, it is meant the pressure of the explosive mixture in the crankcase. In accordance with the present invention, there is detachably mounted on each relief valve 17 a pneumatic shut down device 18 which is provided with a branch air line 19 connected to the main air line 14 for a purpose hereinafter described.

As shown best in FIGS. 2 and 3, the relief valve 17 with which the shut down device 18 is especially adapted to cooperate comprises a frusto-com'cal casing or carrier 20 which is removably secured to the crankcase door 16 by bolts 21 so as to extend outwardly from said door and form a housing for a hemispherical wire gauze assembly 22 which is suitably fastened to a spider 23 having a plurality of radially extending arms the outer ends of which are seated against, and preferably welded to, the inner surface of a radially inwardly directed flange 24 on casing 20. The hub 25 of spider 23 is mounted on a horizontally extending spindle 26 the inner end of which passes through wire gauze assembly 22 and receives a bolt 27 and lock washer 28 which hold the spindle in the position illustrated in FIG. 3. A roll pin 29 extends through the spider hub 25 and spindle 26 to prevent relative rotational movement between these two elements.

The wire gauze assembly 22 is adapted to be oilwetted in any suitable manner so as to serve as a flame trap in the manner described in Patent No. 2,863,512.

The outer end of spindle 26 extends into an inwardly projecting boss 30 formed integrally with the outer vertical wall 31 of a generally dish-shaped valve cover 32, the circumferential wall 33 of which is cut away for approximately of its circumference to provide a downwardly opening gas escape aperture 34. The cover 32 is also provided internally with three equally spaced ribs 35 which extend radially inwardly from circumferential wall 33, the inner edges of which ribs are seated in recesses 36 in the outer peripheral portion of flange 24 of casing 20. The valve cover 32 is secured to the casing by a bolt 37 threaded into the outer end of spindle 26, and a lock washer 38.

In order to control the escape of gas or oil mist from the crankcase outwardly through wire gauze assembly 22 and the outer end of casing 20, a valve disc 40, having a central hub 41, a conical body 42 and a peripheral flange 43, is slidably mounted on spindle 26 within cover 32. The valve disc 40 is yieldably maintained in a closed position, with its flange 43 seating against the outer vertical face of flange 24 of casing 20, by a compression spring 44 the outer end of which surrounds the hub 25 of cover 32 while the inner end surrounds the hub 41 of the valve disc, and which exerts an inward pressure against said disc. The portion of flange 24 of casing 20 which forms the seat for valve disc 40 is preferably recessed to receive an O-ring sealing element 45.

The force exerted by spring 44 against valve disc 40 is so calibrated that, whenever the pressure in the crankcase increases about above 1 lb. per square inch as the result of a crankcase explosion, the valve disc moves outwardly to release the increased pressure, but is quickly closed again to prevent the inflow of air into the crankcase and thereby minimize the possibility of a further explosion and consequent damage to the engine in the event that the engine should continue to operate after the first explosion, a result which the present invention prevents. Leakage of gas or oil mist through the sliding clearance between valve disc hub 41 and spindle 26 is prevented by fitting the hub with an O-ring sealing element 46 having engagement with the spindle.

Referring now to FIGS. 3, 4 and 5, the automatic shut down device 18 of this embodiment is essentially an air pressure release valve having a one-piece rectangular body 50 adapted to be detachably mounted on the vertical wall 31 of valve cover 32 by screws 51 Which pass through countersunk bores 52 in the body 50 and have their inner ends threaded into wall 31. The body 50 includes an upwardly extending cylindrical boss 53 which is internally threaded to receive an air inlet nipple 54 having an axial bore 55. The hexagonal head 56 of nipple 54 is also internally threaded to receive a fitting 57 carried by the lower end of branch air line 19, the upper end of which is provided with a suitable coupling 58 (FIGS. 1 and 2) for connecting line 19 to the main air line 14.

A cylindrical chamber 59 extends downwardly from the lower end of the threaded bore of boss 53 along the central axis of body 50 for approximately half its height, and is provided at its lower end with an annular valve seat 60, preferably of' buna rubber, on which a ball valve 61 is yieldably seated by a compression spring 62, thus normally closing the lower end of chamber 59. Beneath the valve seat 60 is a cylindrical passage 63, coaxial with but of less diameter than chamber 59, which extends to the bottom of body 50 and communicates with a pair of horizontal exhaust passages 64 which extend laterally through the body 50 and open into the atmosphere.

Inasmuch as the spring 62 normally maintains the ball valve 61 in closed position on its seat 60, the pressurized air supplied to the shut down device 18 through line 19 and the axial bore 55 of nipple 54 is contained in the chamber 59 and cannot escape to the atmosphere through exhaust passages 64. However, in accordance with the present invention, the shut down device 18 comprises means which are operable automatically upon opening of relief valve 17 to open ball valve 61, whereupon the air in line 14 escapes to the atmosphere through branch line 19, thereby reducing the pressure in line 14 sufficiently to cause closure of the pressure responsive fuel control valve 13 which in turn shuts down the engine.

For the latter purpose, the shut down device 18 includes a vertically disposed lift pin 65 in passage 63 the upper end of which is of smaller diameter than the opening in valve seat 60 and extends into said opening in position to contact the bottom of ball valve 61. The lower end of lift pin 65 below exhaust passages 64 is of enlarged diameter and extends downwardly in passage 63 into engagement with the central portion of an actuating rod 66 which is slidably mounted in body 50 in a horizontal bore 67 extending perpendicularly to exhaust passages 64, with the ends of said rod projecting outwardly from opposite sides of the body. As indicated in FIGS. 2 and 3, when the shut down device 18 is mounted on the relief valve 17, the axis of actuating rod 66 is parallel to that of spindle 26, and the rod is so positioned that the inner end thereof is closely adjacent to, but spaced from, the flange 43 of valve disc 40. There is thus no direct connection between the relief valve and the actuating rod.

As shown best in FIG. 4, the inner end of actuating rod 66 is provided with an abutment tip 68 having threaded engagement with the rod 66 and carrying a lock nut 69 so that the position of tip 68 may be adjusted relative to the rod 66 to accommodate valve movements of different distances. Normally, the tip is so adjusted as to leave a space of from A1 to /2 between the outer face of flange 43 of valve disc 49 and the inner face of tip 68. The outer end of rod 66 carries a handle or button 70 for manually returning the rod to its normal position indicated in FIGS. 3 and 4 after a crankcase explosion has occurred, and thereby resetting the shut off device 19. The central portion of actuating rod 66, which normally remains within the body 50 in bore 67, is provided with a cylindrical portion 71 of reduced diameter and an inclined shoulder 72 joining the portion 71 to that part of the rod which extends inwardly toward the relief valve, there being a rectangular shoulder 73 between the other end of portion 71 and the outwardly extending part of rod 66. As shown, the rounded lower end of lift pin 65 normally extends into the recess in rod 66 formed by the reduced diameter portion 71, and is maintained in engagement with the rod by gravity.

As long as the engine 10 is operating normally, the elements of the relief valve 17 and shut off device 18 remain in the positions indicated in FIGS. 35. However, in the event of a crankcase explosion which raises the gas or oil mist pressure in the crankcase above a predetermined value, on the order of 1 lb. per square inch in the present instance, the valve disc 40 of the relief valve moves outwardly from its seat on flange 24 of valve casing 20 to relieve the pressure in the crankcase, and in so doing causes flange 43 of the valve disc to engage the abutment tip 68 of actuating rod 66 and to move the rod outwardly through the bore 67 in body 50 from the normal position illustrated in FIGS. 3-5 to a second position wherein the lift pin 65 is raised, i.e., moved outwardly with respect to the axis of rod 66, sufliciently to open the ball valve 61. During outward movement of the actuating rod, the lower end of lift pin 65 rides up the inclined shoulder 72 into engagement with the portion of rod 66 of greater diameter. When the ball valve opens, the pressurized air in branch line 19 and main line 14 escapes to the atmosphere through passage 63 and exhaust passages 64, and causes a drop in pressure in line 14 suflicient to result in closure of the fuel control valve 13 and stoppage of the engine.

After relief valve 17 has opened in response to a crankcase explosion and the shut down device 18 has been actuated in the manner described above, the valve disc 49 returns to its normal, closed position under the influence of spring 44, but actuating rod 66 of the shut down device remains in the position to which it was moved upon opening of the valve until the rod is returned to its original position by manual operation of button 70. Lift pin 65 then drops into the recessed portion of rod 66, and ball valve 61 closes under the influence of spring 62, whereupon the air prcssure in main line 14 increases to its normal value and reopens fuel control valve 13 so that the engine may be restarted.

Referring now to FIG. 6, there is illustrated therein another embodiment of the invention which includes an electrical shut down device for controlling operation of the engine, instead of the pneumatic device of FIGS. 1-5. Inasmuch as the only difference between the apparatus of FIG. 6 and that of FIGS. l-S resides in the construction of the shut off device itself and its connection into an electrical circuit which controls operation of the engine, FIG. 6 does not include a showing of the engine and the crankcase explosion relief valve with which the shut down device is associated, and it will be understood that these portions of the installation are as shown in FIGS. 1-3 and previously described.

In the modification of FIG. 6, the shut down device 18 comprises a casing 80, adapted to be detachably mounted on the cover of the explosion relief valve by screws 81, in which is supported a microswitch 82 of any suitable construction. The contacts of microswitch 82 are normally open, but are adapted to be closed by upward movement of lift pin 65 when actuating rod 66 is moved outwardly from its normal position due to a crankcase explosion which causes outward movement of relief valve disc 40 and abutment of the flange 43 thereof against the tip 68' of actuating rod 65'. Microswitch 82 is provided with electrical leads 83 and 84 which are connected, respectively, to ground and to the grounding terminal of the engine magneto 85. With this arrangement, when actuating rod 66' causes closure of the contacts of microswitch 82, the circuit of magneto 85 is grounded and thus automatically causes the engine to shut down due to lack of ignition. As in the embodiment of FIGS. l5, the engine cannot be restarted until actuating rod 66' is manually reset so as to open the microswitch contacts and remove the ground from the magneto circuit.

FIG. 7 illustrates a modification of the electrical shut down device of FIG. 6 wherein a microswitch 82 is utilized to control the operation of a solenoid operated fuel supply valve 90 located in the fuel line 11' leading to the engine, comparable to the pressure responsive fuel control valve 13 of FIGS. 1 and 2.

As shown, the solenoid of valve 90 is energized from the main power supply line through leads 91, 92 and 93, lead 91 directly connecting one side of the power supply to the solenoid, lead 92 connecting the other side of the power supply to a relay 94, and lead 93 running from the relay to the solenoid. Relay 94 is in turn energized by the low voltage output of a transformer 95 via a lead 96 running directly from one output terminal of the transformer to the relay, a lead 97 connecting the other output terminal of the transformer to one of the contacts (not shown) of microswitch 82', and a third lead 98 connecting the other contact of the microswitch to the relay. This embodiment of the invention is adapted to function either with the contacts of microswitch 82' normally closed and the relay 94 normally energized to deliver power to the solenoid of valve 90 to open the valve electrically, or with the microswitch contacts normally open and the relay 94 normally deenergized to interrupt the supply of power to the solenoid, the valve in this instance being opened mechanically and closed by the solenoid. In either case, outward movement of actuating rod 66 due to a crankcase explosion raises lift pin 65' and changes the contacts of microswitch 82' from one condition to the other so as to effect closure of solenoid valve 90, thus shutting off the supply of fuel to the engine. Again, as in the other embodiments, the engine cannot be restarted until actuating rod 66' is manually reset so as to restore the microswitch contacts to their normal condition and thereby effect opening of valve 90.

Although three specific forms of automatic shut down devices have been described and illustrated in the accompanying drawings, it will be obvious that the invention is not limited to the particular devices shown, but is capable of a variety of mechanical and electrical embodiments. Various changes, which will now suggest themselves to those skilled in the art, may be made in the 6 form, details of construction and arrangement of the parts of the respective devices without departing from the inventive concept. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. Apparatus for shutting down an internal combustion engine having a crankcase upon the occurrence of a crankcase explosion therein, comprising a relief valve assembly adapted to be mounted on the crankcase having a valve seat and a valve member normally maintained in closed position but movable outwardly from said seat in response to an increase in the pressure of the explosive mixture in the crankcase in excess of a predetermined value, and means actuated by outward movement of said valve member for shutting down the engine.

2. Apparatus as claimed in claim 1 wherein said means for shutting down the engine includes an actuating member movable by said valve member upon outward movement thereof from said valve seat from a first position in which the engine is operable normally to a second position in which the engine is inoperable.

3. Apparatus as claimed in claim 1 wherein said means for shutting down the engine includes a body fixed to 5 said valve assembly, and an actuating rod slidably mounted in said body with the ends of said rod extending outwardly from opposite sides of the body, one end of said rod being engageable by said valve member upon outward movement thereof from said valve seat so as to move said rod from a first position in which the engine is operable normally to a second position in which the engine is inoperable, the other end of said rod being manually engageable so as to move said rod from said second position to said first position.

4. Apparatus as claimed in claim 3 wherein said one end of said rod is normally spaced from said valve member a distance less than the distance through which said valve member moves upon the occurrence of a crankcase explosion.

5. Apparatus for shutting down an internal combustion engine having a crankcase upon the occurrence of a crankcase explosion therein, the engine being provided with a pressure responsive device which controls opera tion of the engine and with an air pressure line connecting said device to a source of air under pressure, said apparatus comprising a relief valve assembly adapted to be mounted on the crankcase having a valve seat and a valve member normally maintained in closed position but movable outwardly from said seat in response to an increase in the pressure of the explosive mixture in the crankcase in excess of a predetermined value, and means actuated by outward movement of said valve member for shutting down the engine, said means including an air pressure release valve having an inlet adapted to be connected to said air pressure line and an outlet leading to the atmosphere, means normally maintaining said air pressure release valve in closed position, and an actuating member movable by the valve member of said relief valve assembly upon outward movement thereof from said valve seat for opening said air pressure release valve and thereby causing a drop in pressure in said line.

6. Apparatus as claimed in claim 5 wherein said air pressure release valve has a body fixed to said relief valve assembly, and said actuating member comprises a rod slidably mounted in said body with the ends of said rod extending outwardly from opposite sides of the body, one end of said rod being engageable by said valve member upon outward movement thereof from said valve seat so as to move said rod from a first position in which the engine is operable normally to a second position in which the engine is inoperable, the other end of said rod being manually engageable so as to move said rod from said second position to said first position.

7. Apparatus as claimed in claim 6 including a valve element in said body controlling communication between said inlet and said outlet, yieldable means normally maintaining said valve element in closed position, a lift pin slidably mounted within said body for movement perpendicularly to said rod, one end of said lift pin engaging said rod and the other end being adapted to engage said valve element, and a recess in a portion of said rod intermediate its ends engageable by said one end of the lift pin when said rod is in its first position, whereby movement of said rod to said second position moves said lift pin outwardly with respect to the axis of said rod and thereby opens said valve element.

8. Apparatus for shutting down an internal combustion engine having a crankcase upon the occurrence of a crankcase explosion therein, the engine being provided with an electrical circuit which controls operation of the engine, said apparatus comprising a relief valve assembly adapted to be mounted on the crankcase having a valve seat and a valve member normally maintained in closed position but movable outwardly from said seat in response to an increase in the pressure of the explosive mixture in the crankcase in excess of a predetermined value, and means actuated by outward movement of said valve member for shutting down the engine, said means including an electrical switch adapted to be so connected into said circuit that in one condition of said switch the engine is operable normally and in another condition of said switch the engine is inoperable, and an actuating member movable by said valve member upon outward movement thereof from said valve seat for changing said switch from said one condition to said other condition.

9. Apparatus as claimed in claim 8 wherein said electrical switch has a body fixed to said relief valve assembly, and said actuating member comprises a rod slidably mounted in said body with the ends of said rod extending outwardly from opposite sides of the body, one end of said rod being engageable by said valve member upon outward movement thereof from said valve seat so as to change said switch from said one condition to said other condition, the other end of said rod being manually engageable so as to change said switch from said other condition to said one condition.

10. Apparatus as claimed in claim 9 including a lift pin slidably mounted within said body for movement perpendicularly to said rod, one end of said lift pin engaging said rod and the other end engaging said switch, and a recess in a portion of said rod intermediate its ends engageable by said one end of the lift pin when said rod is in its first position, whereby movement of said rod to said second position moves said lift pin outwardly with respect to the axis of said rod and thereby changes said switch from said one condition to said other condition.

References Cited UNITED STATES PATENTS 2,600,810 6/1952 St. Lucas 123--198 2,714,883 8/1955 Metzger 123-198 3,260,253 7/1966 De Saulniers 123198 3,261,336 7/1966 St. Lucas et a1. 123---198 FOREIGN PATENTS 100,423 2/1962 Netherlands.

487,497 12/1953 Italy. 1,108,982 6/1961 Germany.

WENDELL E. BURNS, Primary Examiner. 

1. APPARATUS FOR SHUTTING DOWN AND INTERNAL COMBUSTION ENGINE HAVING A CRANKCASE UPON THE OCCURRENCE OF A CRANKCASE EXPLOSION THEREIN, COMPRISING A RELIEF VALVE ASSEMBLY ADAPTED TO BE MOUNTED ON THE CRANKCASE HAVING A VALVE SEAT AND A VALVE MEMBER NORMALLY MAINTAINED IN CLOSED POSITION BUT MOVABLE OUTWARDLY FROM SAID SEAT IN RESPONSE TO AN INCREASE IN THE PRESSURE OF THE EXPLOSIVE MIXTURE IN THE CRANKCASE IN EXCESS OF A PREDETERMINED VALUE, AND MEANS ACTUATED BY OUTWARD MOVEMENT OF SAID VALVE MEMBER FOR SHUTTING DOWN THE ENGINE. 